cards.pl

$total=0;
for ($trial=1;$trial<=10000;$trial++) {
     $answer=1+int(rand()*52);
     print "Trial: $trial\tAnswer: $answer\tGuesses: ";
     $guess=-1; $tries=0;
     while ($guess != $answer) {
         $guess=1+int(rand()*52);
         $tries++;
     }
     print "$tries\n";
     $total+=$tries;
}

print "".($total/10000)."\n";

tries.pl

# how many tries until you are 50% likely to have found the card
while ($total<.5) {
    $total+=1.0/52.0 * (51.0/52.0)**$i++;
}

print "$i $total\n";